1. Field of the Invention
The present invention relates generally to producing energetic materials in a carbon dioxide environment. More specifically, the carbon dioxide environment is comprised of a supercritical and/or liquid carbon dioxide environment to form nitrating compounds and/or nitrate substrate materials into energetic materials. Most particularly, the present invention forms nitrogen pentoxide in a carbon dioxide environment that nitrates an appropriate substrate to an energetic material. The liquid carbon dioxide environment provides a nontoxic medium that acts as a heat sink for the chemical reaction occurring therein, and a separation medium for the resulting nitrated chemical compositions.
2. Brief Description of the Related Art
The synthesis and processing of energetic materials, in many cases, require that low temperatures be used. Selective nitration of materials with acid-sensitive moieties are commonly performed with N.sub.2 O.sub.5 at low temperature in halogenated solvents. U.S. Pat. No. 4,985,584 (Millar et al.) discloses a process for the production of high energy materials using inert solvents such as a chlorinated alkane, while U.S. Pat. No. 5,136,062 (Millar et al.) discloses a method for the preparation of nitrate esters of epoxy alcohols in an inert organic solvent using halogenated alkanes such as C.sub.1 -C.sub.2 chloroalkanes and C.sub.1 -C.sub.2 chlorofluoroalkanes. U.S. Pat. No. 5,145,974 (Paul et al.) discloses the preparation of nitratoalkyl-substituted cyclic esters using N.sub.2 O.sub.5 in an organic solvent, such as a C.sub.1 -C.sub.2 chloroalkane of carbon tetrachloride, chloroform, methylene chloride, ethylene dichloride and dichloromethane. These compounds are toxic solvents, volatile organic compounds (VOC), ozone depleting substances (ODS), and/or hazardous air pollutants (HAP). In view of the foregoing, there is a need for a solvent that provides environmentally benign synthesis and processing methodologies for energetic materials manufacturing.